Supply items for laser printers are regularly replaced during printer lifetime. However, to relatively ensure their proper placement, varieties of schemes have been introduced. For example, some laser toner cartridges include a series of tabs molded on a cartridge housing. Depending whether the cartridge includes cyan, magenta or yellow colored toner, patterns of tabs are broken off that allow mating with corresponding patterns of slots in the printer. If users attempt to improperly seat or load a cartridge in the wrong position, the unbroken or remaining tabs interfere with the pattern of slots and insertion is prevented. While approaches like these fairly accomplish the task of minimizing improper loading, their manufacturing process adds steps for marking break-off patterns and requires extra tools, and spacing, to grasp and break the tabs according to the pattern. Broken tabs also add material costs for they are routinely discarded. Ergonomically, molding residue with broken tabs is unsightly and tends to require a relatively large profile.
In other designs, pattern-mating cartridges and printer slots are such that users can insert wrongly colored cartridges a fair distance before mechanical lockout or insertion prevention occurs. Because the distance is sometimes lengthy, the toner of the supply item may have already inadvertently mixed with imaging components relating to a different colored toner. Intuitively, this causes messiness and poor color registration. Still other designs leave to users the actuation of mixing toner of supply items with imaging components. Because of human imperfection, users sometimes inadvertently begin toner mixing before it is assured that the supply item is properly located in a given color slot or properly seated. This too can cause messiness or poor color registration.
Accordingly, there exist needs in the art for simplifying supply item manufacturing (original or refilled) and installing same. Naturally, any improvements should further contemplate good engineering practices, such as relative inexpensiveness, mechanical stability, low complexity, etc.